Strollers are a well known and common way of transporting babies or young children. However, due to their size, strollers typically have collapsible frames that fold into a more compact configuration for storage or to be stowed in a vehicle.
In an effort to achieve a more compact folded configuration, some collapsible strollers have particularly complex hinged and telescopic frame structures. While this may provide a compact folded form, the complexity of the frame increases the production costs. Furthermore, added complexity of the frame tends to weigh against a smooth and reliable folding mechanism. For parents of young children, this operation needs to occur as quickly and simply as possible.
Many countries have official design standards and regulations that apply to strollers. These require the frame to meet certain strength and rigidity thresholds while avoiding hazards such as finger traps and so on. The strength requirement specified by the official standards mean that steel or aluminium alloy are the traditional choices for frame material. However, from the perspective of material costs and high-volume production, polymer frames would be more desirable. Polymers have the added advantage of being lightweight, easily moulded into ergonomic shapes and coloured for greater aesthetic appeal. However, to meet the required strength and structural standards, the polymer would need to be an exotic composite and prohibitively expensive. Alternatively, a cheaper (and weaker) polymer would need to be formed in large cross sections which defeats the purpose of a compact collapsible stroller.
With these issues in mind, there is a need for a collapsible stroller with a predominantly polymer frame that meets the high strength and structural requirements of the official standards, while smoothly, simply and reliably collapsing into a compact folded form.